It is important to remove the heat generated by various apparatuses in the immediate vicinity of the apparatuses in order to minimize the power necessary to conduct air temperature regulation in a cleanroom, and in order to reduce the operating costs of the cleanroom. The main parts of a common apparatus cooling system are shown in FIG. 4; such a system comprises municipal water water tank 1, circulation pump 2, strainer 8, heat exchanger 7, and piping, and conducts the removal of heat from the apparatuses using municipal water at a temperature within a range of 20.degree.-25.degree. C.
However, because various substances are dissolved or dispersed in municipal water, when municipal water is used as cooling water, the following problems occur. For example, suspended matter contained in the municipal water, such as sand, dirt, silica, or the like accumulates in the piping, and may lead to the blockage of the piping. Accordingly, in order to remove the suspended matter present in the cooling water, a strainer 8 is attached upstream from the use point; however, it is impossible to remove all suspended matter, and thus very small suspended matter which is able to pass through the strainer accumulates steadily in the piping, and this finally leads to the blockage of the piping.
On the other hand, Ca ions and the like are also dissolved in municipal water, and when this is heated at the use point, calcium carbonate, which is not readily soluble, is produced, and this is precipitated and adheres to the piping walls. Furthermore, dissolved silica components are also steadily precipitated and adhere to the inner walls of the piping. As a result, the cooling efficiency decreases markedly, and furthermore, water flow resistance increases.
The problems stated above are present when municipal tap water is used in apparatus cooling systems, and thus in order to solve this problem, attempts have been made to use pure water from which all precipitated matter has been removed in place of the municipal water. However, in such cases, while obstructions occurring as the result of the precipitation of suspended matter or the accumulation of dirt or the like were eliminated, problems occurred in which bacterial strains appeared and multiplied within the apparatus cooling system. The bacteria which appeared were attached to the interior of the piping and the heat exchanger, in the same way as the suspended matter and the precipitated matter above, and thus the heat exchanging efficiency was reduced, and an increase in water flow resistance within the piping system was experienced, and blockage of the piping system eventually occurred.
In light of the above circumstances, the present invention has an object thereof to provide an apparatus cooling system which utilizes pure water from which suspended matter and precipitated matter have been removed as the apparatus cooling water, and which suppresses the appearance of bacteria, has high cooling efficiency, and is easy to maintain.